Such a visual field determination is carried out by means of a perimeter in such a manner that the patient rigidly fixes a fixed point, a so-called fixation point, faded in on an image plane; at the same time testing points are offered to the patient at various areas of the visual field, and the patient is then supposed to indicate by pressing a key or verbally whether he/she recognizes the respective testing point. The offering of the testing points is done either manually or automatically, the result of the measurement is subsequently entered into a test protocol or is manually or automatically registered, processed and printed out by a computer.
This testing process is stressful in particular for older patients since the examination of many visual field positions requires a longer period of time and the rigid fixation of a fixation point is nonphysiological, tiresome and uncomfortable.